Supplemental Information - Property, Plant And Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2018
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 1,263,072	$ 1,255,518
Less: accumulated depreciation	672,030	658,795
Property, plant and equipment, net	591,042	596,723
Depreciation	64,500	60,700	$ 67,100
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	39,585	35,165
Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 14,998	14,149
Buildings And Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	20 years
Property, plant and equipment, gross	$ 88,349	86,444
Vehicles, Including Transport Trailers [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	105,184	111,283
Bulk Equipment And District Facilities [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	111,019	109,751
Tanks, Cylinders And Customer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	784,466	779,827
Computer And Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	112,582	111,838
Construction In Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 6,889	7,061
Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	2 years
Minimum [Member] | Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	2 years
Minimum [Member] | Vehicles, Including Transport Trailers [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	8 years
Minimum [Member] | Bulk Equipment And District Facilities [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	5 years
Minimum [Member] | Tanks, Cylinders And Customer Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	2 years
Minimum [Member] | Computer And Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	2 years
Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	30 years
Maximum [Member] | Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	20 years
Maximum [Member] | Vehicles, Including Transport Trailers [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	20 years
Maximum [Member] | Bulk Equipment And District Facilities [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	30 years
Maximum [Member] | Tanks, Cylinders And Customer Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	30 years
Maximum [Member] | Computer And Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	5 years
Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 1,263,072	1,255,518
Less: accumulated depreciation	672,030	658,795
Property, plant and equipment, net	591,042	596,723
Depreciation	64,500	60,700	$ 67,100
Ferrellgas, L.P. [Member] | Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	39,585	35,165
Ferrellgas, L.P. [Member] | Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 14,998	14,149
Ferrellgas, L.P. [Member] | Buildings And Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	20 years
Property, plant and equipment, gross	$ 88,349	86,444
Ferrellgas, L.P. [Member] | Vehicles, Including Transport Trailers [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	105,184	111,283
Ferrellgas, L.P. [Member] | Bulk Equipment And District Facilities [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	111,019	109,751
Ferrellgas, L.P. [Member] | Tanks, Cylinders And Customer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	784,466	779,827
Ferrellgas, L.P. [Member] | Computer And Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	112,582	111,838
Ferrellgas, L.P. [Member] | Construction In Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 6,889	$ 7,061
Ferrellgas, L.P. [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	2 years
Ferrellgas, L.P. [Member] | Minimum [Member] | Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	2 years
Ferrellgas, L.P. [Member] | Minimum [Member] | Vehicles, Including Transport Trailers [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	8 years
Ferrellgas, L.P. [Member] | Minimum [Member] | Bulk Equipment And District Facilities [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	5 years
Ferrellgas, L.P. [Member] | Minimum [Member] | Tanks, Cylinders And Customer Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	2 years
Ferrellgas, L.P. [Member] | Minimum [Member] | Computer And Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	2 years
Ferrellgas, L.P. [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	30 years
Ferrellgas, L.P. [Member] | Maximum [Member] | Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	20 years
Ferrellgas, L.P. [Member] | Maximum [Member] | Vehicles, Including Transport Trailers [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	20 years
Ferrellgas, L.P. [Member] | Maximum [Member] | Bulk Equipment And District Facilities [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	30 years
Ferrellgas, L.P. [Member] | Maximum [Member] | Tanks, Cylinders And Customer Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	30 years
Ferrellgas, L.P. [Member] | Maximum [Member] | Computer And Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	5 years